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String Object (JavaScript)

JavaScript - Internet Explorer 10

Allows manipulation and formatting of text strings and determination and location of substrings within strings.

newString = new String(["stringLiteral"])

Parameters

newString: Required. The variable name to which the String object is assigned.
stringLiteral: Optional. Any group of Unicode characters.

Remarks

JavaScript provides escape sequences that you can include in strings to create characters that you cannot type directly. For example, \t specifies a tab character. For more information, see Special Characters (JavaScript).

String Literals

A string literal is zero or more characters enclosed in single or double quotation marks. A string literal has a primary (primitive) data type of string. A String object is created by using the new Operator, and has a data type of Object.

The following example shows that the data type of a string literal is not the same as that of a String object.

JavaScript

var strLit = "This is a string literal.";
var strObj = new String("This is a string object.");

document.write(typeof strLit);
document.write("<br/>");
document.write(typeof strObj);
// Output:
// string
// object

Methods for String Literals

When you call a method on a string literal, it is temporarily converted to a string wrapper object. The string literal is treated as though the new operator were used to create it.

The following example applies the toUpperCase method to a string literal.

JavaScript

var strLit = "This is a string literal.";

var result1 = strLit.toUpperCase();

var result2 = (new String(strLit)).toUpperCase();

document.write(result1);
document.write("<br/>");
document.write(result2);
// Output: 
// THIS IS A STRING LITERAL.
// THIS IS A STRING LITERAL.

Accessing an Individual Character

You can access an individual character of a string as a read-only array-indexed property. This feature was introduced in Internet Explorer 9 standards mode, Internet Explorer 10 standards mode, and win8_appname_long apps. The following example accesses individual string characters.

JavaScript

var str = "abcd";
var result = str[2];
document.write (result);
// Output: c

var result = "the"[0];
document.write(result);
// Output: t

Requirements

The String Object was introduced in Internet Explorer before Internet Explorer 6. Some members in the following lists were introduced in later versions.

Properties

The following table lists the properties of the String object.

Property	Description
constructor Property	Specifies the function that creates an object.
length Property (String)	Returns the length of a String object.
prototype Property	Returns a reference to the prototype for a class of objects.

Functions

The following table lists the functions of the String object.

Function	Description
String.fromCharCode Function	Returns a string from a number of Unicode character values.

Methods

The following table lists the methods of the String object.

Method	Description
anchor Method	Places an HTML anchor that has a NAME attribute around text.
big Method	Places HTML <BIG> tags around text.
blink Method	Places HTML <BLINK> tags around text.
bold Method	Places HTML <B> tags around text.
charAt Method	Returns the character at the specified index.
charCodeAt Method	Returns the Unicode encoding of the specified character.
concat Method (String)	Returns a string that contains the concatenation of two supplied strings.
fixed Method	Places HTML <TT> tags around text.
fontcolor Method	Places HTML <FONT> tags with a COLOR attribute around text.
fontsize Method	Places HTML <FONT> tags with a SIZE attribute around text.
hasOwnProperty Method	Returns a Boolean value that indicates whether an object has a property with the specified name.
indexOf Method (String)	Returns the character position where the first occurrence of a substring occurs within a string.
isPrototypeOf Method	Returns a Boolean value that indicates whether an object exists in another object's prototype chain.
italics Method	Places HTML <I> tags around text.
lastIndexOf Method (String)	Returns the last occurrence of a substring within a string.
link Method	Places an HTML anchor that has an HREF attribute around text.
localeCompare Method	Returns a value that indicates whether two strings are equivalent in the current locale.
match Method	Searches a string by using a supplied Regular Expression object and returns the results as an array.
propertyIsEnumerable Method	Returns a Boolean value that indicates whether a specified property is part of an object and whether it is enumerable.
replace Method	Uses a regular expression to replace text in a string and returns the result.
search Method	Returns the position of the first substring match in a regular expression search.
slice Method (String)	Returns a section of a string.
small Method	Places HTML <SMALL> tags around text.
split Method	Returns the array of strings that results when a string is separated into substrings.
strike Method	Places HTML <STRIKE> tags around text.
sub Method	Places HTML <SUB> tags around text.
substr Method	Returns a substring beginning at a specified location and having a specified length.
substring Method	Returns the substring at a specified location within a String object.
sup Method	Places HTML <SUP> tags around text.
toLocaleLowerCase Method	Returns a string in which all alphabetic characters are converted to lowercase, taking into account the host environment's current locale.
toLocaleString Method	Returns an object converted to a string, using the current locale.
toLocaleUpperCase Method	Returns a string in which all alphabetic characters are converted to uppercase, taking into account the host environment's current locale.
toLowerCase Method	Returns a string in which all alphabetic characters are converted to lowercase.
toString Method	Returns the string.
toUpperCase Method	Returns a string in which all alphabetic characters are converted to uppercase.
trim Method	Returns a string with leading and trailing white space and line terminator characters removed.
valueOf Method	Returns the string.

Reference

new Operator (JavaScript)

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